/* Keep continuously redrawn canvases out of a filtered full-stage surface.
   The paper, cover and their existing 3-D choreography remain independent. */
@media (min-width:801px) {
 /* The journey is a scroll playhead, not a scrolling surface. Keeping its
    viewport fixed avoids moving a sticky clip over the masked 3-D leaves. */
 .stage { position:fixed; inset:0; height:100svh; }
 .ocean-world { filter:none; }
 .env-cove,.env-library { filter:blur(calc(var(--reading-focus) * 7px)); }
 /* Retain the environments while they are in a crossfade. Invisible scenes
    must not retain animated masks, filters and offscreen texture surfaces. */
 .environment[data-render-active="false"],
 .coral-wipe[data-render-active="false"],
 .passage-bridge[data-render-active="false"],
 .launch-atmosphere[data-render-active="false"] { visibility:hidden; }
 /* A transparent WebGL canvas still owns a full-screen compositor surface.
    Retire it outside the creature passage, including the whole book scene. */
 #jelly-life[data-render-active="false"] { display:none; }
 .continuous-passage[data-environment="library"] #marine-life { filter:none; }
}